1. Field of the Invention
The present invention relates to a system and method for quickly re-establishing long distance telephone service after a long distance carrier's end office has been rendered inoperable by a disaster.
2. Related Art
The telephone system that exists today in the United States includes local exchange companies and long distance carriers which provide local telephone service and long distance telephone service, respectively, to users. The local exchange companies (LEC) each include a plurality of LEC offices. Users' telephones and other telephonic devices (such as facsimile machines) are connected to these LEC offices.
The long distance carriers each include a plurality of central offices connected to one another by a long distance telephone network. A local exchange company's LEC offices are connected to a long distance carrier's central offices.
A long distance telephone call represents a connection from a user's telephone to the LEC office in the local exchange company, to the long distance carrier's central office, and then to the long distance telephone network. The call is routed through the long distance telephone network to the destination location, where the connection continues through the central office and the LEC office situated at the destination location, and finally to the destination telephone.
As is apparent from the above discussion, a local exchange company's LEC office (and all users connected to that LEC office) obtain access to the long distance telephone network via the long distance carrier's central office. Thus, from the perspective of that LEC office (and, again, all users connected to the LEC office), the long distance carrier's central office represents a gateway to long distance communication with the outside world. This gateway closes if the central office becomes inoperable. If the gateway closes, then users connected to the LEC office (that is connected to the inoperable central office) become shut off from long distance communication with the outside world.
Various factors will cause a central office to become inoperable. Some of these factors are minor and can be remedied in a timely manner. For example, a few components in the central office may break down, thereby rendering the central office either partially or completely inoperable. In this case, the central office can be quickly and easily restored to service by repairing or replacing the components.
Other factors are major and result in the central office being inoperable for an extended period of time. For example, the central office may be severely damaged (perhaps completely destroyed) by a natural disaster such as an earthquake, a flood, a fire, a tornado, etc. Also, the central office may be severely damaged by a system failure that damages most of the components in the central office, such as a system-wide electrical failure.
Recovery from a major failure is conventionally handled in the same way as recovery from a minor failure. The damaged central office is repaired (or, in some cases, completely re-built). Such repairs may take months. During this time, users connected to the LEC office (that is connected to the inoperable central office) are shut off from long distance communication with the outside world. Thus, this conventional approach for restoring service after a major failure is flawed since it denies to users long distance telephone capability for an extended period of time.
In reality, users adversely affected by the inoperable central office are not entirely shut off from long distance communication since they can utilize the long distance services provided by other long distance carriers while the LEC office is being prepared. However, these users may not return to the original long distance carrier (that is, the long distance carrier that owns the inoperable central office) once the central office is restored to service. Thus, the above-described conventional approach for restoring service after a major failure is further flawed since it causes the original long distance carrier to lose customers.
Thus, what is required is a system and method for quickly re-establishing long distance telephone service after a long distance carrier's central office has been rendered inoperable by a disaster.